Board Foot Calculator
Board feet from thickness (in) × width (in) × length (ft) ÷ 12, for one board or a stack, with hardwood quarters, a waste allowance and the cost. How it works
Use the Board Foot Calculator
About the Board Foot Calculator
One board foot is 144 cubic inches, a piece 1 in thick, 12 in wide and 1 ft long. Board feet = thickness (in) × width (in) × length (ft) ÷ 12, so a 2x6 that is 8 ft long is 8 board feet, and so is a 1x12 at 8 ft. The board foot calculator multiplies by the number of boards, adds a waste allowance and prices the total at your price per board foot, or works out the cost per board foot from the total you paid.
Board feet per board by size and length
| Size (in) | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 1x4 | 2.67 | 3.33 | 4 | 5.33 |
| 1x6 | 4 | 5 | 6 | 8 |
| 1x8 | 5.33 | 6.67 | 8 | 10.67 |
| 1x12 | 8 | 10 | 12 | 16 |
| 2x4 | 5.33 | 6.67 | 8 | 10.67 |
| 2x6 | 8 | 10 | 12 | 16 |
| 2x8 | 10.67 | 13.33 | 16 | 21.33 |
| 2x10 | 13.33 | 16.67 | 20 | 26.67 |
| 2x12 | 16 | 20 | 24 | 32 |
| 4x4 | 10.67 | 13.33 | 16 | 21.33 |
Thickness × width as written, in inches, × length in feet ÷ 12, rounded to two decimals. The calculator uses the size you enter, so enter the size your supplier prices on.
Hardwood in quarters: board feet of one 8 ft board
| Thickness | 4 in wide | 6 in wide | 8 in wide |
|---|---|---|---|
| 4/4 (1 in) | 2.67 | 4 | 5.33 |
| 5/4 (1.25 in) | 3.33 | 5 | 6.67 |
| 6/4 (1.5 in) | 4 | 6 | 8 |
| 8/4 (2 in) | 5.33 | 8 | 10.67 |
The quarters picker fills the thickness field: 4/4 is 1 in, 5/4 is 1.25 in, 6/4 is 1.5 in and 8/4 is 2 in.
Frequently asked questions
- How do you calculate board feet?
- Multiply the thickness in inches by the width in inches and the length in feet, and divide by 12. A 2 in × 6 in board 8 ft long is 2 × 6 × 8 ÷ 12 = 8 board feet. For several boards of the same size, multiply by the number of boards.
- How many board feet is a 2x4x8?
- 5.33 board feet, from 2 × 4 × 8 ÷ 12. A 2x4 that is 12 ft long is 8 board feet and one that is 16 ft long is 10.67.
- What do 4/4 and 8/4 mean in lumber?
- Thickness in quarters of an inch: 4/4 is 1 in, 5/4 is 1.25 in, 6/4 is 1.5 in and 8/4 is 2 in. Pick one in the quarters list and it fills the thickness field. For thicker stock, type the inches yourself: 10/4 is 2.5 and 12/4 is 3, so one 12/4 board 6 in wide and 8 ft long is 12 board feet. The thickness field takes any value up to 24 in.
- How much does lumber cost by the board foot?
- The calculator has no prices: enter the price your supplier charges per board foot. 20 boards of 4/4 stock, 6 in wide and 8 ft long, are 80 board feet, which at $6.50 a board foot is $520.00. Working from an invoice instead? Leave the price empty and enter Total cost paid: $132 for 10 boards of 2 × 6 × 8 with 10% waste (88 board feet) is $1.50 a board foot.
- How do I convert a price per MBF to a price per board foot?
- MBF means a thousand board feet, so divide the MBF price by 1,000: $1,200 per MBF is $1.20 per board foot, and $850 per MBF is $0.85. Enter that in Price per board foot. One 2x6 that is 8 ft long is 8 board feet, so at $1.20 it costs $9.60, and 10 of them cost $96.00.
- Does the waste allowance change the cost?
- Yes, the price is applied to the board feet with waste. 12 boards of 5/4 stock, 8 in wide and 10 ft long, are 100 board feet. At $7.25 a board foot that is $761.25 with 5% waste, $797.50 with 10% and $870.00 with 20%.
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